KR20210037378A - High temperature superconducting wire manufacturing method and High temperature superconducting wire with multiple superconducting layers using the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a high temperature superconductor, and a high temperature superconductor having multiple superconducting layers using the same. The method for manufacturing a high temperature superconductor comprises: a stacking step for stacking superconductors such that protection layers of a pair of superconductors including at least a substrate-superconducting layer-protection layer face each other; a bonding step for heat-treating the stacked pair of superconductors such that the protection layers facing each other are diffusion-bonded to each other to form a bonded protection layer; a peeling step for removing a layered structure on the upper side of a superconducting layer on one side of the superconductor on which the bonded protection layer is formed, thereby exposing the superconducting layer to the outside; and an outermost protection layer forming step for forming an outer protection layer, made of the same material as the bonded protection layer, on the upper side of the superconducting layer exposed to the outside through the peeling step. According to the present invention, it is possible to form multiple superconducting layers by easily stacking additional superconducting layers according to the required current density, and paste of the same material as the protection layers can be filled into gaps between the stacked protection layers through a paste filling process and heat-treated together with the protection layers, and thus there is an advantage in that the superconducting layer and the substrate can be effectively separated in the process of peeling the substrate.

Description

High temperature superconducting wire manufacturing method and high temperature superconducting wire with multiple superconducting layers using the same}

The present invention relates to a method of manufacturing a high-temperature superconducting wire having a multilayer structure in a form in which a plurality of superconducting layers are stacked, and a high-temperature superconducting wire having multiple superconducting layers using the same.

The superconducting phenomenon is a physical phenomenon in which the resistance of a material approaches zero below a critical temperature, and a superconducting wire manufactured using it has excellent characteristics in terms of conducting high current and generating a high magnetic field.

Such characteristics of the superconducting wire can improve product performance and implement miniaturization. Therefore, superconducting wires are used in various industrial fields such as development of power devices such as superconducting magnets, superconducting cables, superconducting motors, and superconducting generators, as well as medical equipment development such as NMR and MRI, and development of large scientific equipment such as accelerators and nuclear fusion devices. There is a steady effort to do it.

Meanwhile, the superconducting wire is classified into a low temperature superconductor (LTS) and a high temperature superconductor (HTS) based on a critical temperature.

Among them, the high-temperature superconducting wire (HTS) exhibits superconducting characteristics at a relatively high temperature with a critical temperature of around 100K (-173℃) compared to the low-temperature superconducting wire (LTS) with a critical temperature close to the absolute temperature of 0K (-273℃). , It is mainly manufactured and used in a thin film type.

In general, thin-film high-temperature superconducting wires are manufactured by forming a plurality of buffer layers on a metal substrate and laminating a superconducting layer on top of the buffer layer by a physical or chemical method, and if necessary, a protective layer on the upper side of the superconducting layer. And a stabilizing layer may be additionally deposited.

The thin-film type high-temperature superconducting wire having such a configuration has difficulty in conducting a high current of 1000A or more as the superconducting layer is formed as a single layer. Accordingly, efforts have been made to form a multi-layered structure by assembling a plurality of superconducting wires in order to conduct a high current through the high-temperature superconducting wire.

Meanwhile, the most common method for assembling superconducting wires is a method of connecting the superconducting wires in parallel by soldering them to each other.

However, in the case of aggregation by soldering, the resistance between wires is relatively high, leading to deterioration of superconducting performance, and as the overall resistance of the aggregated superconducting wire is not uniform, such as peeling of the soldering part, the flow of current is reduced. To one side, there is a problem that the superconducting state may be broken as the internal temperature of the superconducting wire increases due to excess.

Therefore, in order to solve this problem, in the prior art, the superconducting wire is connected in the longitudinal direction, or the superconducting wire is electroplated around the superconducting wire using a stabilizing material, the filaments between the multi-core superconducting wires are bonded, or the billet-shaped superconducting wire is stabilized again. Techniques have been developed to reduce the resistance of the normal conductive part by soldering, such as coating with a molten wire.

However, such conventional techniques require high time and cost, and when a separate superconducting wire or other electrical connection device is to be connected to the superconducting wire to which the metal stabilizing material is bonded, the soldering process is again performed, and the heat generated at this time is Problems such as separation of the superconducting wire and the previously soldered part have occurred due to an effect on the already soldered part.

On the other hand, in order to solve the above problems, in the "Laminated superconducting wire bonding method and superconducting wire unit (KR 1845474 B1) laminated and bonded through the same," copper (Cu) in a region where a plurality of superconducting wires are stacked with each other in a vacuum atmosphere. ) A technique is published in which particles are vacuum evaporated to form a copper stabilizing layer between superconducting wires and bond them.

In detail, FIG. 1 is a diagram illustrating a bonding process of stacked superconducting wires according to the prior art.

Referring to FIG. 1, in order to form a superconducting layer into multiple layers, first, the surfaces of the plurality of superconducting wires 11 and 12 are cleaned (S1a), and the plurality of superconducting wires 11 and 12 are inserted into the vacuum chamber in a spaced state. (S2a), and after vacuum deposition (S3a) of the pure copper particles 10 between the superconducting wires, passing through a pressure roller to form the copper particles 10 into the copper stabilizing layer 13 (S4a). It goes through.

Even if the stacked superconducting wire material manufactured through the above-described steps moves from room temperature to cryogenic temperature, peeling of the copper stabilization layer 13 due to a difference in thermal expansion coefficient can be prevented, and relatively high current conduction is possible.

However, in the case of forming a superconducting layer of two or more layers, a plurality of superconducting wires can be charged in a spaced state and manufactured by performing the same process. However, in the case of additionally stacking a superconducting layer, heat is applied to the copper stabilizing layer 13. As the interfacial strength is lowered, it is difficult to perform additional heat treatment on the superconducting wire.

In addition, when a plurality of superconducting layers is formed, a plurality of buffer layers and substrates are formed together with the superconducting layer, thereby increasing the overall thickness of the stacked superconducting wire.

On the other hand, a peeling technique can be applied as a method for solving the problem of increasing the thickness.

2 is a reel-to-reel separation system according to the prior art, and a technique of mechanically separating the superconducting layer after increasing the stress level between the superconducting layer and the buffer layer by applying an external action is disclosed.

To this end, the prior art peeling system includes a plurality of reels (41, 42, 43) for winding a superconducting wire, a plurality of idler rollers (61, 62, 63, 64) for applying tension, and an induction for increasing the stress level. The coil 52 is configured to include a stepper motor 51 and a tape guide 53 for stable transfer of the superconducting wire.

That is, the separation system according to the prior art applies stress to the superconducting wire in the process of transferring the superconducting wire through the reels 41 and the reels 42 and 43 to reduce the bonding force between the buffer layer and the superconducting layer. Peeling off. In this case, the stress applied to the superconducting wire is thermal stress caused by an external source such as the inductive coil 52, infrared or radio frequency radiation.

Therefore, in the case of applying thermal stress as described above, a wire rod coated with a stabilizing layer, that is, a copper (Cu) layer, is preferable. As stress is applied to the superconducting wire, it is difficult to perform multiple peeling processes.

KR 10-1845474 B1 KR 10-2019-0051009 A

It is an object of the present invention to provide a method of manufacturing a high-temperature superconducting wire in which a plurality of superconducting wires individually manufactured are laminated and bonded to form a plurality of superconducting layers.

Another object of the present invention is to provide a method of manufacturing a high-temperature superconducting wire capable of reducing the thickness of a high-temperature superconducting wire in which a plurality of superconducting layers are stacked.

Another object of the present invention is to provide a high-temperature superconducting wire having multiple superconducting layers in which the ratio of superconducting layers per unit area is increased.

The present invention for achieving the above object is a lamination step of laminating a superconducting wire such that a pair of superconducting wires including at least a substrate-superconducting layer-protective layer face each other, and a heat treatment of the stacked pair of superconducting wires. A bonding step in which the facing protective layers are diffusion bonded to each other to form a bonding protection layer, and peeling of removing the layered structure on the upper side of the superconducting layer so that the superconducting layer on one side of the superconducting wire on which the bonding protection layer is formed is exposed to the outside. And forming an outermost protective layer of the same material as the bonding protective layer on the upper side of the superconducting layer exposed to the outside through the peeling step and the step of forming an outermost protective layer.

In another aspect, the present invention provides a second superconducting wire comprising a substrate-a first buffer layer-a first superconducting layer-a first protective layer and a substrate-a second superconducting layer-a second protective layer. A lamination step in which a protective layer is stacked to face each other with the first protective layer, a bonding step in which the stacked first and second protective layers are diffusion bonded to each other by heat treatment to form a bonding protective layer, and the second superconducting layer A peeling step of removing the layered structure above the second superconducting layer so as to be exposed to the outside, and forming an outer protective layer of the same material as the bonding protective layer on the upper side of the second superconducting layer exposed to the outside. And an additional lamination step of laminating the N-th protective layer of an N-th superconducting wire including a substrate-N-th superconducting layer-N-th protective layer to face the outer protective layer, and the stacked outer protective layer and the N-th protective layer. An additional bonding step in which the layers are diffusion bonded to each other by heat treatment to form an additional bonding protection layer, and an additional peeling step of exposing the Nth superconducting layer to the outside by removing the layered structure above the Nth superconducting layer, and the additional peeling An additional outermost protective layer forming step of forming an outer protective layer of the same material as the additional bonding protective layer on the upper side of the Nth superconducting layer exposed through the step, wherein the additional lamination step, the additional bonding step, and the additional peeling step And the outermost protective layer forming step is characterized in that it is repeatedly performed N-2 times depending on the number of superconducting layers stacked. (Where, N is a natural number of 3 or more)

According to the present invention having the above characteristics, it is possible to form multiple superconducting layers by easily stacking a superconducting layer according to the required current density.

In addition, since a metal stabilization layer and a buffer layer can be easily added, a layered structure can be formed in various ways according to required physical properties.

In addition, AC loss may be reduced by separation of the superconducting layer by the bonding protection layer, and separation of the bonded portion due to the difference in the thermal expansion coefficient may be prevented as the bonding interface does not exist due to diffusion bonding.

In addition, before the formation of the bonding protective layer, the gap between the stacked protective layers through the paste filling process is filled with a paste of the same material and heat-treated together, so that the superconducting layer and the substrate can be effectively separated in the process of peeling the substrate. It has the advantage of being able to.

1 is a view for showing a bonding process of stacked superconducting wires according to the prior art.
2 is a reel-to-reel separation system according to the prior art.
Figure 3 is a flow chart for showing the manufacturing process of the high-temperature superconducting wire according to the present invention.
Figure 4 is a view for showing the manufacturing process in each step according to Figure 3;
5 is a cross-sectional view showing a stacked structure in each step according to FIG. 3.
6 is a flow chart showing another embodiment of the bonding step, which is an essential part of the present invention.
FIG. 7 is a view for showing differences in substrate peeling according to the embodiment of FIG. 6.
8 is a photograph for showing a state in which the substrate is separated using a winding bobbin.
9 is a flow chart for showing an additional lamination process of the high-temperature superconducting wire according to the present invention.
10 is a cross-sectional view showing an embodiment of various high-temperature superconducting wires according to the present invention.
11 is a scanning electron microscope (SEM) photograph for showing the structure and interface of the quadruple stacked structure by the method of manufacturing a high-temperature superconducting wire according to the present invention.
12 is a graph showing the measurement result of the critical current of the high-temperature superconducting wire according to the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to elements of each drawing, the same elements are denoted by the same numerals as possible even if they are indicated on different drawings. It is described. In addition, in the description of the embodiment, when it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment of the present invention, the description has been simplified or omitted, and a component is placed on the upper side of the other component. When stated as “equipped”, “laminated”, “formed” or “coated”, the component may be provided, laminated, formed or coated directly on the top surface of the other component, but between each component It should be understood that the components may be “equipped”, “laminated”, “formed” or “coated”.

The method of manufacturing a high-temperature superconducting wire according to the present invention is a process of forming multiple superconducting layers using a single-layered superconducting wire, and bonding and peeling a plurality of superconducting wires including a substrate-superconducting layer-protective layer under atmospheric pressure. It can be formed by performing it repeatedly.

In detail, FIG. 3 is a flow chart showing the manufacturing process of the high-temperature superconducting wire according to the present invention, FIG. 4 is a diagram showing the manufacturing process of each step according to FIG. 3, and FIG. A cross-sectional view for showing the stacked structure according to each step is shown.

Referring to these drawings, the manufacturing process of the high-temperature superconducting wire 900 according to the present invention is first made using a plurality of superconducting wires including a substrate-superconducting layer-protective layer, and hereinafter, for convenience of description, The first superconducting wire 510 and the second superconducting wire 520 are divided into N-th superconducting wires and described as N-th superconducting wires (where N is a natural number of 3 or more).

In detail, in the method of manufacturing the high-temperature superconducting wire 900 according to the present invention, first, a first substrate 110-a first buffer layer 210-a first superconducting layer 420-a first protective layer 610 Prepare a second superconducting wire 520 composed of a first superconducting wire 510 and a second substrate 120-a second buffer layer 220-a second superconducting layer 440-a second protective layer 620 Thus, a lamination step (S100) of laminating the first protective layer 610 and the second protective layer 620 is performed.

For easier and efficient lamination, in this embodiment, the first and second superconducting wires 510 and 520 are prepared in a state wound on the first supply reel 330 and the second supply reel 350, respectively. When is completed, a lamination step (S100) of laminating the first and second superconducting wires 510 and 520 so that the first and second protective layers 610 and 620 face each other is performed.

In the lamination step (S100), the first and second protective layers of the first and second superconducting wires 510 and 520 supplied from the first supply reel 330 and the second supply reel 350 using the winding bobbin 310 ( 610 and 620 are stacked while being wound around the winding bobbin 310 in the form of pancakes so that they face each other.

When stacking in the form of pancakes using the winding bobbin 310 as described above, the stacking can be performed while applying a certain tension, so that the first and second protective layers 610 and 620 may be more closely contacted.

Meanwhile, after the lamination step (S100) is performed as described above, the bonding step (S200) of forming the bonding protective layer 600 by heat treatment of the stacked first and second superconducting wires 510 and 520 is performed.

In the bonding step (S200), heat treatment is performed in a state in which the first and second superconducting wires 510 and 520 are wound around the winding bobbin 310. Here, since the first and second protective layers 610 and 620 are formed of a thin film coated with silver (Ag), surface oxidation does not occur even when exposed to the atmosphere.

Therefore, it is possible to heat-treat the winding bobbin 310 by using a heating means without a separate vacuum chamber, and the heated first and second protective layers 510 and 520 are diffusion-bonded to one bonding protective layer 600 without an interface. ) Is formed.

Meanwhile, in the bonding step (S200), the heat treatment is performed in a temperature range of 400°C to less than 600°C.

When the heat treatment is heated to a temperature range of less than 400°C, diffusion bonding between the first and second protective layers 610 and 620 does not occur completely, so that the formation of the bonding protection layer 600 is not smooth, and the temperature exceeds 600°C. In this case, the first and second superconducting layers 420 and 440 may lose superconducting properties. Therefore, in the step of forming the bonding protection layer (S200), heating is performed within the above temperature range so that plastic deformation does not occur and bonding can be performed using diffusion of atoms.

When the bonding step (S200) as described above is completed, the first substrate 110-the first buffer layer 210-the first superconducting layer 420-the junction protective layer 600-the second superconducting layer 440-the second One superconducting wire having a stacked structure including the buffer layer 220-the second substrate 120 is formed in a state wound around the winding bobbin 310.

Meanwhile, in the present invention, a peeling step (S300) for removing the layered structure above the superconducting layer to be exposed is performed in order to expose the superconducting layer on one side so that the superconducting layer can be further stacked in the above state.

In detail, the peeling step (S300) is a preparation process for additionally laminating a superconducting layer through the additional formation of the bonding protection layer 600 described above. In this embodiment, the second superconducting layer 440 in the second superconducting wire 520 ), and the second substrate 120 and the second buffer layer 220 are separated (delamination).

In the peeling step (S300) according to the present invention, a peeling method of separating the superconducting layer by applying a physical force in the atmosphere is applied.

In detail, looking at the interlayer bonding structure in the laminated structure formed through the bonding step (S200), the structure in which the bonding protection layer 600, which is a noble metal, is bonded to the superconducting layer, which is ceramic, has a relatively strong bonding force. The structure in which the superconducting layer and the ceramic buffer layer are bonded has a relatively weak bonding force.

Therefore, when the second substrate 120 is torn off with a physical force, the bonding protection layer 600 and the second superconducting layer 440, which have a relatively strong bonding force, maintain a firmly coupled state, and the bonding force is relatively weak. The second buffer layer 220 and the second substrate 120 are separated from the second superconducting layer 440.

On the other hand, in this embodiment, such a peeling step (S300) is performed using the winding bobbin 310, the wire recovery reel 320, and the substrate recovery reel 340.

The substrate recovery reel 340 is rotated by fixing the second substrate 120 of the laminated wire supplied from the winding bobbin 310, and the second buffer layer 220 separated from the second superconducting layer 440 and The combined second substrate 120 is recovered.

As described above, the wire recovery reel 320 includes the first substrate 110, which is left as the second substrate 120 is recovered, the first superconducting layer 420, the junction protective layer 600, and the second superconducting layer 440. ), and the wire rod of the laminated structure is recovered.

At this time, in order to more easily recover the second substrate 120, in the bonding step (S200), the end of the second substrate 120 is bonded to protrude outward compared to other layers, and in the peeling step (S300) By fixing the second substrate 120 protruding as described above to the substrate recovery reel 340 and rotating it, peeling can be made more easily.

On the other hand, the metal substrate for manufacturing the superconducting thin film wire is subjected to an electrolytic polishing process to planarize the substrate in the manufacturing process.At this time, when the edge portion is etched a lot by the electric field concentrated in the edge portion, the edge of the metal substrate is rounded. Can be.

Further, in the case of a superconducting wire manufactured using such a substrate, when the superconducting wire is peeled using physical force, there may be a case where the superconducting layer is not smoothly separated at the edge of the superconducting layer.

In detail, FIG. 6 is a flow chart showing another embodiment of the bonding step, which is an essential component of the present invention, and FIG. 7 is a view showing the difference in peeling of the substrate according to the embodiment of FIG. 6, and FIG. Figure 8 shows a picture to show the state in which the substrate is separated using the winding bobbin.

First, referring to FIG. 7, the first and second superconducting layers 420 and 440 and the first and second protective layers 610 and 620 respectively formed on the first and second substrates 110 and 120 with rounded corners are Both the first and second substrates 110 and 120 are formed to be round along the shape of the corners.

Accordingly, when stacked in the above-described shape, gaps 690 are formed at the edges of the first and second protective layers 610 and 620.

The gap 690 exists even after the bonding protection layer 600 is formed, and when the second substrate 120 is pulled using a physical force in this state, the second substrate 120 is peeled as shown on the left side of FIG. 7. ), the residual superconducting layer 440' remains together and appears as a loss.

Therefore, in order to eliminate such loss, a paste filling process (S210) of filling the gap 690 with the paste 680 of the same material as the first and second protective layers 610 and 620 may be further performed. .

In the process of filling the paste (S210), the first and second protective layers 610 and 620 are wound to face each other in the form of a fan case through the stacking step (S100). It is made by filling the paste 680.

When the paste filling process (S210) is completed as described above, heat treatment is performed similarly to the bonding step (S200) described above, and at this time, the paste 680 filled in the region corresponding to the gap 690 and the first and second protections As the interfaces between the layers 610 and 620 are diffusion bonded together, a bonding protection layer forming step (S220) formed of one bonding protection layer 600 is performed.

As described above, when the second substrate 120 is separated after the second substrate 120 is formed as one layer up to the portion corresponding to the gap 690, as shown in the right side of FIG. Separation is effectively performed, and this can be confirmed through a picture of the cleanly separated substrate shown in FIG. 8.

On the other hand, when the peeling step (S300) is performed, the second superconducting layer 440 is exposed to the outside, and on the upper side of the exposed second superconducting layer 440, additional stacking of a superconducting wire or reinforcing mechanical properties is performed. The outer protective layer forming step (S400) is performed so that the stacking can be performed.

The outer protective layer forming step (S400) is a step of thinly coating a protective layer of the same material as the bonding protective layer 600 on the upper surface of the outermost superconducting layer exposed to the outside by the peeling step (S300). When the formation of the layer 800 is completed, the first substrate 110-the first buffer layer 210-the first superconducting layer 420-the junction protective layer 600-the second superconducting layer 40-the outer protective layer ( A high-temperature superconducting wire 900 composed of 800 is formed.

Meanwhile, as described above, a superconducting layer may be additionally stacked on the high-temperature superconducting wire 900 formed as described above. On the other hand, when there is no additional layering, the outer protective layer 800 forms the outermost protective layer, and a stabilization layer forming step for reinforcing mechanical properties is performed.

That is, according to the present invention, a high-temperature superconducting wire 900 can be provided by repeatedly stacking a superconducting layer according to the current density required in the application field, and when the requirement of the current density is satisfied, a metal coating layer such as a copper stabilizing layer is formed. This reinforces mechanical properties.

Hereinafter, an additional lamination step (S500) for additionally laminating a superconducting layer on the high-temperature superconducting wire 900 will be described.

FIG. 9 is a flow chart showing an additional stacking process of a high-temperature superconducting wire according to the present invention, and FIG. 10 is a cross-sectional view showing various embodiments of a high-temperature superconducting wire according to the present invention.

Referring to these drawings, when an additional superconducting layer is to be laminated on the high-temperature superconducting wire 900 manufactured through the above-described steps S100 to S400, first and second superconducting layers 420 and 440 and the outer protective layer A process of preparing a high-temperature superconducting wire 900 including 800 and a superconducting wire to be additionally stacked (S510) is performed.

In the process (S510), the high-temperature superconducting wire 900 is supplied through one supply reel, and additionally stacked superconducting wires are prepared to be supplied through another supply reel.

When the above process (S510) is completed, the high-temperature superconducting wire 900 and the superconducting wire additionally stacked on the winding bobbin 310 are wound and stacked in the form of a pancake. At this time, the outer protective layer 800 and the outer protective layer 800 are additionally stacked. A process in which the protective layers (not shown) of the superconducting wire are stacked to face each other (S520) is performed.

When the process (S520) is completed, the process of forming an additional bonding protection layer (S530) through heat treatment is performed, and at this time, the above-described paste filling process (S210) and the bonding protection layer formation process (S220) are additionally bonded protection. It may be added before the process of forming a layer (S530).

On the other hand, when the process (S530) is completed, a process (S540) of peeling the layered structure of the upper layer of the superconducting layer including the substrate of the additionally stacked superconducting wire is performed, and on the upper side of the additionally stacked superconducting layer exposed to the outside The process of forming the outer protective layer 800 (S550) is performed again to form a high-temperature superconducting wire having a three-layer superconducting structure.

In addition, the processes of S510 to S550 may be repeatedly performed according to the current density required in the application field, and may appear in various embodiments as shown in FIGS. 10 and 11.

The high-temperature superconducting wire 910 shown in FIG. 10A is a first substrate 110-a first buffer layer 210-a first superconducting layer 420 in a form in which the additional lamination step S600 is performed three times. -Junction protective layer 600-Second superconducting layer 440-Junction protective layer 600a-Third superconducting layer 460-Junction protective layer 600b-Fourth superconducting layer 480-Junction protective layer ( 600c)-the fifth superconducting layer 490-the outer protective layer 800 is formed.

And, after the multi-structure of the superconducting layer is formed as described above, it may be formed of a high-temperature superconducting wire 920 including a metal coating layer 710 as shown in FIG. 10B, wherein the metal is copper, Bronze, brass, stainless steel, etc. can be applied.

On the other hand, the high-temperature superconducting wire 930 shown in FIG. 10(c) is a form in which the first substrate 110 is removed from the high-temperature superconducting wire 910 shown in FIG. 10(a), and FIG. 10(d) ) Is formed in a form including a metal coating layer 720 on the high-temperature superconducting wire 930, and such a form may be appropriately used according to the application field.

In addition, (e) of FIG. 10 is a soldering 730 and an additional metal substrate 130 on the outer surface of each of the high-temperature superconducting wires 910, 920, 930, and 940 corresponding to FIGS. 10A to 10D. 140) is added, and in the case of such a structure, a high-temperature superconducting wire 950 having improved mechanical strength may be formed.

Hereinafter, a more specific embodiment of the high-temperature superconducting wire manufactured through the above process will be described.

<Example>

A pair of 12mmw superconducting wires composed of a metal substrate-a buffer layer-a superconducting layer-a protective layer and a protective layer coated with silver (Ag) were prepared.

The prepared superconducting wire is wound on an Inconel circular winding bobbin, which is a winding bobbin, and a pair of superconducting wires are wound with a pancake so that the silver protective layer faces each other.

At this time, the dummy wire is co-winding, and the dummy wire is wound with a 005t×10mmw LMO coated Hastelloy wire.

3kgf로 10turn 정도 권선한 후 초전도선재 한 쌍을 보호층이 마주보도록 적층한 다음 더미선재를 co-winding 한다. 이때 더미선재를 추가로 30turn 정도 감아서 풀리는 것을 방지한다.The dummy wire rod is used as a winding method.

After winding about 10 turns at 3kgf, stack a pair of superconducting wires with the protective layer facing each other, and then co-wind the dummy wires. At this time, an additional 30 turns of the dummy wire are wound to prevent loosening.

The wound superconducting wire is taken out after oxygen heat treatment at 500° C. for about 3 hours, and through this, the laminated protective layer is diffusion bonded into one layer in a state in which the interface does not exist.

After that, when the superconducting wire is separated by physical force, the protective layer is bonded into a single layer. Therefore, the relatively weakly bonded superconducting layer and the buffer layer are separated from each other to form a metal-buffer layer-superconducting layer-protection layer-superconducting layer. The superconducting wire and the wire made of a metal substrate-buffer layer are separated.

In this way, silver (Ag) is coated as a protective layer on the top of the superconducting wire exposed with the superconducting layer, and then winding and heat treatment are repeated on the bobbin together with other superconducting wires to bond the protective layer into one layer. A superconducting wire in which a superconducting layer is repeatedly laminated can be obtained by repeating the separation of the wire material consisting of a metal substrate-buffer layer or a metal deep plate from

FIG. 11 shows a scanning electron microscope (SEM) photograph to show a quadruple-stacked structure and interface by the method of manufacturing a high-temperature superconducting wire according to the present invention, and a superconducting layer and a bonding protective layer (shown as Ag in FIG. 11) ) Are not separated from each other, and it is possible to confirm the solidly stacked state.

In addition, FIG. 12 is a graph showing the measurement result of the critical current of the high-temperature superconducting wire having multiple superconducting layers according to the present invention. The actual measured width of the superconducting wire is 1mm or 10mm when converted into a critical current value of 980A/cmw. You can see that comes out.

As described above, according to the method of manufacturing a high-temperature superconducting wire according to the present invention, it is possible to easily manufacture a high-temperature superconducting wire having multiple superconducting layers in a desired multi-layered form.

That is, in the case of the high-temperature superconducting wire 900 in which N superconducting layers are formed on the upper side of the substrate according to the required current density, the first buffer layer 200, the first superconducting layer 420, and The bonding protection layer 600 and the second superconducting layer 440 are stacked as a basic structure. Further, based on this, N-2 junction protective layers and N-th superconducting layers are alternately provided on the upper side of the second superconducting layer 440, and an outer protective layer is included on the upper side of the last superconducting layer. (Where, N is a natural number of 3 or more)

On the other hand, when the superconducting layer is additionally laminated, the outer protective layer is diffusion bonded to the protective layer of the superconducting wire to be laminated by heat treatment to form an additional bonding protective layer, and if not further laminated, the outermost protective layer is formed. Thus, various multilayer structures can be formed by allowing a stabilizing layer for reinforcing mechanical properties to be formed thereafter.

100.......... Substrate 110.......... First Substrate
120.......... 2nd substrate 200.......... Buffer layer
210.......... The first buffer layer 220.......... The second buffer layer
310.......... Winding bobbin 320.......... Wire rod recovery reel
330.......... 1st supply reel 340.......... Substrate recovery reel
350.......... 2nd supply reel 420.......... 1st superconducting layer
440.......... 2nd superconducting layer 460.......... 3rd superconducting layer
480.......... 4th superconducting layer 490.......... 5th superconducting layer
510.......... 1st board 520.......... 2nd board
600, 600a, 600b, 600c...........
610.......... First protective layer 620.......... Second protective layer
680.......... paste 800.......... outer protective layer

Claims (8)

A lamination step of laminating a superconducting wire such that a pair of superconducting wires including at least a substrate-superconducting layer-protective layer face each other;
A bonding step of heat-treating the stacked pair of superconducting wires to form a bonding protection layer while the facing protection layers are diffusion bonded to each other;
A peeling step of removing the layered structure above the superconducting layer so that the superconducting layer on one side of the superconducting wire is exposed to the outside; And
A method of manufacturing a high-temperature superconducting wire material comprising: forming an outermost protective layer formed of the same material as the bonding protective layer on an upper side of the superconducting layer exposed to the outside through the peeling step. The second protective layer of the second superconducting wire including the substrate-the second superconducting layer-the second protective layer on the first superconducting wire including the substrate-the first buffer layer-the first superconducting layer-the first protective layer is the first A lamination step of laminating the protective layer to face each other;
A bonding step in which the stacked first and second protective layers are diffusion bonded to each other by heat treatment to form a bonding protective layer;
A peeling step of removing the layered structure above the second superconducting layer so that the second superconducting layer is exposed to the outside;
An outer protective layer forming step of forming an outer protective layer of the same material as the bonding protective layer on an upper side of the second superconducting layer exposed to the outside; And
An additional lamination step of laminating the N-th protective layer of an N-th superconducting wire including a substrate-N-th superconducting layer-N-th protective layer to face the outer protective layer;
An additional bonding step in which the stacked outer protective layer and the N-th protective layer are diffusion bonded to each other by heat treatment to form an additional bonding protective layer; And,
An additional peeling step of removing the layered structure above the Nth superconducting layer so that the Nth superconducting layer is exposed to the outside; And
And an additional outermost protective layer forming step of forming an outer protective layer of the same material as the additional bonding protective layer on the upper side of the Nth superconducting layer exposed through the additional peeling step, and,
The method of manufacturing a high-temperature superconducting wire, characterized in that the additional lamination step, the additional bonding step, the additional peeling step, and the additional outermost protective layer forming step are repeatedly performed N-2 times depending on the number of superconducting layers stacked. Is a natural number greater than or equal to 3) The method according to claim 1 or 2,
A method of manufacturing a high-temperature superconducting wire, characterized in that the step of forming a stabilizing layer is performed when there is no additional superconducting layer after the outer protective layer is formed. The method of claim 1,
After the lamination step, a paste filling process is performed to fill the gaps (Gab) between the stacked protective layers with the same material, so that both the interface between the protective layers and the interface between the protective layer and the filled paste during heat treatment in the bonding step A method of manufacturing a high-temperature superconducting wire, characterized in that diffusion bonding is performed to form one bonding protection layer. The method of claim 2,
After the lamination step and after the additional lamination step, a paste filling process in which the gap (Gab) between the first and second protective layers and the gap (Gab) between the Nth protective layer and the outer protective layer are filled with the same material, respectively. A method of manufacturing a high-temperature superconducting wire, characterized in that each of these is performed. It is formed by the method of manufacturing the high-temperature superconducting wire of claim 2,
With the substrate,
A first buffer layer provided on the upper side of the substrate,
A first superconducting layer provided above the first buffer layer,
A bonding protective layer provided on the upper side of the first superconducting layer,
A second superconducting layer provided on the upper side of the bonding protection layer,
N-2 junction protective layers and N-th superconducting layers are alternately provided above the second superconducting layer,
Finally, a high-temperature superconducting wire having multiple superconducting layers, characterized in that it comprises an outer protective layer provided on the top of the stacked superconducting layer (where N is a natural number of 3 or more). The method of claim 6,
The bonding protection layer and the outer protection layer are silver (Ag), gold (Au), platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), osmium (Os), and rhenium. A high-temperature superconducting wire having multiple superconducting layers, characterized in that it is formed of any one of (Re) or formed by a mixed composition thereof. The method of claim 6,
A high-temperature superconducting wire having multiple superconducting layers, further comprising a metal coating layer covering both the substrate and the outer protective layer.

Images